There is loss of fertile top soil because of the productivity of agricultural crops, vegetation; forests lead to soil erosion. So soil erosion is a natural and normal process by which the earth's crust is constantly eroded under the forces of weathering.
Main causes of soil erosion:
The major causes of soil erosion are as follows:
Excessive Rain fall:
Due to excessive rain fall, top fertile soil washed away.
Human activities accelerate disappearance of protective cover of natural vegetation and cause soil erosion. It is artificial erosion.
Over grazing leads to the absence of ground-vegetation, cause gradual depletion of soil organisms, and cause soil erosion.
It causes soil erosion by rapid rain fall and the flow of wind.
Such mining activities such as open cast mining and underground mining lead to soil erosion.
Open cast Mining: One cast mining helps in the complete removal of soil and leads to the destruction of the total land area, loss of productive area and soil erosion is caused.
Underground Mining: Underground mining leads to the whole area a depression and it becomes a waste land. It also causes run off acids which crude soil. The toxic chemicals from solid wastes are absorbed by soil and may kill plants and animals.
It causes Stalinization and soil erosion.
Use of chemical Fertilizers:
By continuous use of fertilizers, and high use increases nutrient contamination is runoff water and ground water. Nitrate becomes toxic to animals and results decrease in soil fertility thus cause soil erosion.
Use of pesticides:
By the process of using pesticides beneficial soil organisms like earth worms are killed which cause soil infertile.
As forests are slashed and burnt it reduces humus content and the water holding capacity of soil is lost. So cultivators move to another patch of forests for fresh cultivation. The resulting exposure of soil to rain and wind causes drastic soil erosion.